Need some help with a problem on the auto tool zero for the Z axis. I have had it working for over a year and a half on Mach Blue V3.2 , but today it quit on me. It worked correctly for a couple of times this morning and them seemed to loose its mind. Now when I select the Z axis touch button, it starts down slowly and moves for about a quarter of an inch, set for 2 inch max, stops then rapids further down for apx another quarter of an inch and then moves up to 1.25 and indicates in the message box that the axis has been zeroed. This all happens without it touching the touch pad. If I manually touch the tool with the pad, it recognizes the pad and again rapids further down and then back to 1.25.
  The only thing I have done different today was to calibrate the Z axis using the Set Steps Per Unit feature in the Settings Menu which I have used in the past without any problem. I had a hard copy of the script file which I used to compare with the file in the computer and everything appears ok.
Tried rebooting several times, but it didn’t help.
I would really appreciate any suggestions as to where to start to isolate the problem.

Thanks in advance.
Richard

Noise is triggering the probe input. You won't see the LED when this happens, as it's too fast.

Gerry,
Thanks for the response. How do you go about filtering out the noise?

Gerry,
Went down and checked it this morning and it no longer plunges down. When I select the Z touch button it starts as it normally would and then stops without contacting the touch pad and raises one inch.

A lot of people add a capacitor across the input. Ideally, proper grounding techniques would eliminate the issue.

If the message tells you that it has been zeroed, then noise is triggering it.

Thanks for the help, I will dig around and see what I can find.